Manufacture of flexible metal tubing.



E. IAIVIES.

MANUFACTURE 0F FLEXIBLE METAL TUBING.

APPLICATION FILED AUGJO. i911.

Patented May 13, 1919.

3 SHEETS-SHEET I.

I L y- I M F L ,L 5.@ W m E. JAIVIES.

MANUFACTURE 0F FLEXIBLE METAL TUBING.

APPLICATION FILED AUG.I0. |911. I,303,674 n Patented May 18, 1919.

3 SHEETS-SHEET 2.

I I I4 IIIIIIIII lm] Illllllu L I I4 E. JAMES. MANUFACTUHE OFIFLEXIBLE METAL TUBING. APPLICATION FILED Aucmo. IQII.

1,303,674. Patented May 13, 1919.

3 SHEETS-SHEET 3.

I4 /I/c/V 7101/ 1 79 Effi/@rdf Smeg EDWARD JAMES, OIF LAKEWOOD, OHIO.'

MANUFACTURE 0F FLEXIBLE METAL TUBING.

raoaera.

` Specification of Letters Patent.

Patented May 13, 1919.

Original application led October 10, 1910, Serial No. 586,157. Divided and this application filed August 10,

1917. Serial No. 185,444.

To all whom it may concern:

Be it known that l, EDWARD JAMES, a

.citizen of the United States, and a resident of Lakewood, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in the Manufacture of Flexible Metal Tubing, of which the following is a specification, the principle of the invention bein herein explained and the best mode in w ich l have contemplated applying that principle, so as to distinguish it from other inventions.

My invention, relating as indicated to the manufacture of flexible metal tubing, is more particularly concerned with the manufacture of flexible metal tubing about a conductor in order to produce an armored conductor or the like, such. asare now demanded by underwriters and others to prevent injury to the insulation of the conductor. The present invention; covers a part of the subject matter described and claimed in a co-pending application filed October 10, 1910, Serial No. 586,157.

. The present invention can be more readily understood by a general description of my improved/method, followed by a description ofthe present adaptation of that method to the manufacture of 'armored conductors. To the accomplishment of the foregoing objects, then, said invention consists of the steps hereinafter fully described and particularly pointed out in the claims.

The annexed drawings illustrate one form of means whereby my improved method may be advantageously practised, and the follow-` ing descriptionv sets forth in detail the preferred method of practising my invention.

ln said annexed drawings Figure 1 is a perspective View of a piece of tubing in course of formation; Fig. 2 is a side elevation of one approved construction of machine'for carrying out the method of manufacture constituting the invention; Fig. 3 is a transverse sectional View thereof taken on the line 3 3, Fig. 2; Fig. 4 is a broken detail view, on a like enlarged scale, of two of said rolls; Fig. 5 isan enlarged sectional view of the mandrel and two of the rolls that coperate therewith, the plane of the section being indicated by the line 5 5, Fig. 2; Fig. 6 is similarly a transverse sectional view taken on the line 6 6, Fig. 2; Figs. 7 and 8 are views, corresponding with Fig.l 5, and respectively showing two modifications in .it is coiled, are forced between the convo-lu tions of the outer coil W.

The ceiling mechanism proper of the form of machine just referred to as particularly designed for use in my improved method of manufacture, comprises in the form illus trated, a short mandrel 1, (Figs. 2 and 5), that is preferably rotatably mounted in a suitable supportin head 2. It is not intended to positively rive such4 mandrel, however, but simply to leave it free to rotate 'under the action of the coil being formed thereon. vSaid mandrel, in the form shown in the figures just referred to, comprises two co-aXial, substantially cylindrical sections of unlike diameters, the section'nearest to the head 2, or in other words, adjacent to the supported end of the mandrel, being of larger diameter than the free end.

Said mandrel is furthermore desirably made hollow, `so as' to be adapted to permit of the introduction therein of a suitable lubrica nt,which is preferably maintained underl pressure sufficient to cause it to be gradually discharged through openings 17, 17 in the mandrels cylindrical walls. Such lubricant may be thus suppliedthrough a chamber 18 in the head 2, that provides a convenient reservoir. For many uses it has been found desirable to interiorly lubricate the type of flexible metal tubing, consisting of inter-coiled wires, such as the present machine is adapted to manufacture, not only that the bore of such tube may be thus coated, but also the bearing or contacting portions of the successive convolutions of the .nter-coiled wires. By the foregoing construction, enabling as it does, the introduction of the lubricant and its thorough spread within the convolutions of the coils formed on the respective sections of the mandrel, both of these desirable results are accomplished simultaneously with thc winding of the coils.

Symmetrically disposed about such mandrel, and parallel therewith, are three shafts v 3, 4 and 5, the two lower ,of which (viz.,

shafts 3 and t) are preferably journaled in spaced fixed bearings 6, 6 while the uppermost'is supported in a frame 8 oscillatory about an axis 9 parallel with` the shaft, but capable of support-ing-said shaft at an adjustable distance above the mandrel 1, this distance being gaged by a hand-wheel 10 threaded upon -a vertically disposed screw l1, and bearing upon the free end of said frame through an interposed compression spring 12,

In vaddition to bearings 6, 6 for the shafts provide thrust bearings 7 (Fi 6), to take up any end thrust to which suc shafts 'may be subjected incidentally to the operation of the wire-coilingI rolls respec tively carried thereby;

The function of these rolls is to guide the respective wires W and w, that enter into the making of the tubing, about the mandrel 1 l as well as to maintain themin contact therewhereas the convolutions with. Of such rolls the two lowermost are of substantially similar construction, viz., that shown in Figs. 4, 5 and 6, being composed of two sections, 13 and 14, the first being keyed or otherwise ixedly secured toits shaft, and the other being freely rotatable about such shaft, preferably upon a hub-like extension 15 of the first section. Both Vthese sections are peripherally grooved, so as to provide on their outer, cylindrical faces a series of corrugations 16 concentric with the rolls axis,

one form of corrugation being shown in Figs.

4 and 5. These particular encircling corrugations are designed to engage with the turns of the wire W being coiled on the mandrel section of larger diameter. Accordingly on the portions of the respective rolls that cooperate with themandrel section of larger diameter such corrugations are more closely spaced axially of said rolls, than on the other portions of such rolls which extend beyond the oliset or step between the mandrel sections of larger and smallerdiameter. In other words, the corrugations on the first roll section 13, correspond with the closely crowded turns or convolutions of the iirst coil W as it is vwound on the first mandrel section, on the second roll section correspond with the spaced condition of such convolutions after the second coil has been introduced within the first.

The second, or outer, roll-section 14, then, is provided with elements or ribs 19 lying intermediate between the corrugations 16 just described, which elements are at a greater radial distance .from the rolls axis than the corrugations so as to contact with lthe convolutions of the inner coil w, that is introduced at this stage of theoperation. Preferably, moreover, such elements or ribs of the roll are likewise grooved, so as to present 'corrugations, the more effectively to contact with and form these last-named convolutions. This, however, is not essential and such ribs 0n the second roll section may be left straight if desired, as shown for example in Fig. 9.

Between the two lowermost coiling rolls thus described as substantially identical, 'there exists thisdifference, viz., that the foremost roll, regarding the same in the direction tangent to such mandrel, as clearly shown in Fig. 2. It will be observed, in other words, that if such wire were fed in over the coiling would be introduced in the wire, and that, too, in a direction opposite to the one which it is to receive upon being coiled on the man drel. This result will follow no matter from what direction the wire be brought in between the rolls. Byv the arrangement just described, however, I avoid this entirely land thus save the wire the additional strain that would be imposed upon it by being twice bent upon radii so short and close together.

Similarly a space 21 is left between the two sections 13 and 14 of this foremost roll, through which the second wire w may pass directly on a line tangent to the mandrel, thus avoiding kinking it likewise.

The upper roll of the three coiling rolls is illustrated as being simply an idler; but just as in the case of the two previously described,

is formed of two sections 22 and 23 (see Fig.

machine merely to press down upon the coils of wire bein formed about the mandrel by the two positlvely driven coiling rolls, I have Since this roll is utilized in the presentl roll to the mandrel, an extra bend, or kink,

,found it advisable to dispense with corrugai tions on at least the first section 22 of such roll, inasmuch as a roll with a smooth surface will be just as effective to hold the convolutions ofthe initially formed portion of the outer coil against the mandrel as would a corrugated roll. The second section 23 may likewise be left plain if desired,although,

here, in order to assist in spreading apart the convolutions of theouter coil, thus initially formed closely together, I prefer to employ the corrugations 16 with the raised intermediate ribs 19 adapted to coperate with the inner coil that is now introduced.

It will be understood, of course, that either the rolls or the encircling corrugations thereon are set relatively to each other so that the first corrugation that receives the wire will be a little in advance (or in the rear as one may be pleased to regard it), of the second lili i corrugation, and so on, in order that a proper prefer to secure the offsetting in question by correspondingly offsetting the entire roll, since this is readily accomplished by simply interposing a washer 25 of the proper thickness between the rear edge of the roll and the head or frame in which its shaft is journaled.

Of the three shafts hereinbefore described as bearing thel wire-coiling rolls, the two lowermost along with certain feed-rolls 28 and 29 presently to be described, are driven in unison from a common drive-shaft 26 (Figs. 2, 3 and 6), preferably by means of worm gearing 27, although this obviously is a matter of indi'erence. The intermediate roll, viz., the one carried in the adjustable frame 8 above the mandrel, is `preferably not positively driven, as thisl has been found unnecessary under ordinary operating conditions. It will be readily understood how it can be connected to be positively driven, if desired, from the same shaft as the other two rolls, or'from a countershaft connected therewith. 4

There are two pairs of the feed rolls 28 and 29 just referred to, as shown in Fig. 2,

`such pairs of rolls being laterally spaced from each other so as to feed the wires W and w passing therebetween respectively, at

vthe proper points longitudinally of the inandrel `1;'in other words, the second wire is spaced from the first a distance substantially equal to the length of the mandrel section of larger diameter that projects beyond the mandrel supporting head 2, it being upon this section that the outer wire constituting the tube is initially wound before its convolutions are separated by the introduction of the second coil.

Of these two pairs of feed-roll the lowermost rolls of each are mounted upon shafts 30- and 31, journaled in the frame of the machine and driven, as above indicated, from the main drive-shaft 26 that also drives the two lowermost of the wire-coiling rolls. The upper feed rolls are also positively driven, their shafts32 and 33 being intergeared with the corresponding lower shafts. Such upper shafts, however,are journaled in a comiqon movable frame 34,

preferably one oscilla-tory about an axis 35A transverse to the shafts and adapted to be pressed down under a variable pressure by means of a hand-wheel 36 mounted upon a threaded shaft 37 and operating through an interposed spring 38 similar to that employed in connection with the uppermost coiling roll. v

Intermediately between the respective pairs of feed rolls, that thus feed in the two wires used in forming the tube, and the coiling rolls,.which wind such wires into tubular form, I provide tubes 39 of s'uitable length, through which the wires may pass. These tubes are designed to contain a suitable lubricant, preferably one containing graphite as a constituent, which lubricant maybe supplied as required through a feed opening 40 so that the wires as they are fed forwardly onto the mandrel, or rather into the coiling rolls, are thoroughly coated with the lubricant in question.

While in the preceding reference to the operation of my improved machine it has been implied that the wires are fed directly in between the mandrel and the coperating coiling rolls, this is in practice strictly true only when once the machine has been put in operation. In other words, in order to start the machine, 'it -is desirable to form apart from such machine, a short section of the tubing composed of `one wire coiled within the other, so that this can be placed on the mandrel and the rolls closed thereon. The means whereby such short section of tubing is preparatorily formed are not of present interest, as, they constitute no part of the invention in hand.

A modification of the mechanism hereinbefore described, whereby such mechanism is adapted to coil wire into a flexible me-` tallic tube directly incasing an electrical conductor, or like conduit, is illustrated in Fig. 7 where it will be observed that the modified .mandrel 41 comprises a single section of uniform diameter corresponding with the section of larger diameter in the case of the mandrel previously described, Such mandrel is furthermore open at both ends and the insulated conductor C, which is to be incased, is passed directly therethrough, the diameter of the mandrel bore being properly gaged to fit closely about the conductor. The latter thus replaces, in effect, the mandrel section of smaller diameter and the operation of inter-coiling the two wires` that Ago to make up my improved tubing, may proceed just as before, the outer wire being coiled upon the mandrel section of larger diameter that is retained, while the smallerwire is coiled u-pon the conductor.

The latter, it will be understood, is allowed i to move longitudinally through the mandrel as the inner wire is thus coiled thereon, thus differing from the mandrel section of tion.

The proposition is obviously substantially the same where, instead of the insulated electrical cable, it is desired to armor rubber hose, or any similar object. My improved fieXible metal tubing may be directly formed on such hose in exactly the same fashion as that in which I have just described it as smaller diameter in the preceding construcconductor such as just described, it is adeffectively embedded in the insulation of vantageous to so gage the diameters of the interlocking wire coils, that the convolutions of the inner one shallbe more or less the conductor, since I am thus enabled to use a lighter gage of wire, while still -providing an equally effective cover-in or armor for the conductor. In other wor s, the embedded coil will receive and take up a greater longitudinal strain for a given gage of wire smaller, wire 'w'v as than if it were the inner coil of a simple tube or of such a tube only loosely incasing the conductor.

It is desirable, as before, that the tube should be interiorly lubricated, and to this end the rese-rvoir 18 in the head 2 is constructed soas to permit the conductor to be drawn directly therethrough, it being found that suflicient lubricant will adhere thereto to effect the desired purpose.

A further modification is shown inthev figure Just referred to in that the inner, or

it has beenpreviously termed, is of half-round section, instead of being a circular wire of smaller diameter than outer wire w. It will be understood, of course, that my improved machine is not limited to use-with'any particular cross-section of wire strand; but such strand maybe either circular, or half-round, or angular, as may be found suitable to the production of tubing of the general class in hand.

Thus in Fig. 8 I illustrate the use, for one ofthe wires, of a strand lw2 of triangular cross-section, such strand, moreover, is here shown as being the outeronedespite the fact that it is introduced at a point in the operation corresponding with the introduction of what has in the precedlng cases figured as the interiorV coil. Accordingly, the second i section of the respective rolls is here left plain,

that is, without corrugations and this second wire fw2 simply pressed into place., correspondingly spreading the turns of the interior coil. In this operation no mandrel section of smaller diameter is necessary, and so it is accordingly omitted in the showing of Fig. 8.

It has been previously explained that the elements or ribs between the corrugations 16,

inthe case ofthe second-or .outermost secv tions 14 and 23 of the rolls, may be left smooth, that is, so as to present a cylindrical surface, instead of being concave. The smooth superficial form of these ribs is illustrated in Fig. 9. On the other hand, were a be made With an angular depression to fit the contour of the wire.

In each of the several forms of my improved machine illustrated i'n the drawings hereinbefore described there Will be, owing to the use of the feedl rolls, but little tension, if any, on the wires between such feed rolls and the coiling rolls. It will be understood, however, that in place of thus pushing the wires, as it were, upon the mandrel and simply employing the coiling rolls to bend the same onto such member, I might rely on the frictional engagement of the rolls with the turns of wire about the mandrel to pull the latter, thus making the coiling mechanism proper self-feeding. Under certain operative conditions, moreover, the positive driving of the coiling rolls might be omitted entirely and full reliance placed on the feed rollsto force the wire or wires onto and about the mandrel. j

Where the feeding of the component wires, the interposed convolutions of whose coils go to make up my improved tube, is accomplished by pushing such wires into' the coiling members, whether rolls or dies, the use of the mandrel may be dispensed with. This is in effect exemplilied in the construction shown in Fig. 7, where the second wire may be either pushed in, to directly surround the insulated cable so as to only lightly engage therewith, or Where it may be drawn in about the same by the pulling action of the rolls; in the lirst case the presence of the cable will be only incidental, while in the second it will obviously function as a man- In any case the rolls serve to apply a sufficient lateral pressure to the wire entering therebetween tol form the same into coils with convolutions of the proper diameter; it being in a degree immaterial whether a mandrel be located within the coil to thus determine its diameter, or the mere resilient tendency of the convolutions be depended upon to maintain as large a diameter as possible within the llimits prescribed by such laterally applied ressure.

he term coil throughout the claims, is intended to refer to the respective series of convolutions, and it is obviously immaterial whether the respective coils be formed by one wire or by a plurality of Wires.

The foregoing detailed description has been given for clearness of understanding only and no undue limitation should be understood therefrom, but the appended claims should be construed as broadly as permissible in view of the prior art.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the methods herein disclosed, pro- 'vided the step or steps stated by any one of the following claims or the equivalent of such stated step or steps be employed.

l therefore particularly point out and distinctly claim as my invention 1. ln a methlod of making an armored product of the character described, the steps which consist in coiling a wire about a -conductor in spaced relation therewith, and coiling a second Wire within such irst named spaced wire and i-n yieldable engagement with said conductor.

2. In a method of making an armored product of the character described, the steps 1 which consist in coiling a wire about a conductor in spaced'relation therewith, coiling `wire in said conductor.,

3. In a method of making an armored product of the character described, the steps which consist in ceiling a wire about a conductor in spaced relation therewith, coiling a second wire Within said first named wire and in yieldable contact with said conductor, and simultaneously allowing said conductor to move longitudinally within and in contact with the coil formed by said second wire.

iSigned by me, this 20th day of July, 1917.

EDWARD JAMES. 

